Carburetor



June 25, 1929. w. H. WEBER CARBURETOR Filed March 10 1924 2 Sheets-Sheet1 w Ill... .llll

IN V EN TOR.

- ATTORNEY.

June 25 1929. w, H, WEBER 1.718.769

GARBURETOR Filed March 10, 1924 2 SQeets-Sheet 2 I 60 T Hi; Hi w c ml; Mw i w .97 .17

g if INVENTOR.

' ATTORNEY.

lf atentetl dune ilti, i929 1,718,769 PATENT OFFICE.

WALTER H. WEBER, F HIGHLAND FARR, MICHIGAN, ASSIGNOR TO DETROIT LUBRI-GATUH GUMPANY, 01b DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

GARBURETOB.

Application filed March 10, 1924. Serial No. 698,013.

lily invention relates broadly and generally at 8, into a nipple 8,preferably formed into carburetors, and particularly to those of theplain tube type.

The primary object of the invcntlonus to provide a carburetor of thetype mentioned with improved means for assuring substantially correctmixture porportions of liquid fuel and air throughout the range ofoperative engine speeds and loads.

Tlhe invention consists in the improved construction and combination ofelements, to be more fully described hereinafter, and the novelty ofwhich will be particularly pointed out and distinctly claimed.

lln the accompanying drawings to be taken as a part of thisspecification, have shown a preferred embodimentof the Invention, and inwhich drawings, Figure l is a vertical central section through myimproved carburetor;

Fig. 2 is an enlarged central vertical section through a nozzle assemblyembodying my invention, and as shown in Fig. l;

Fig. 8 is a section on the line 33 of 2;

Fig. t is a section on the line t-l of Fig. 2;

Fig. b is a section on the line 5-5 of Fig. 2;

fig. 6 is a view similar to Fig. l, but showing a modified form ofnozzle;

Fig. 'l is a view similar to Fig. l, and showing another form of nozzle,and

8 is a detailed view in elevation looking from the right of lFig. l,showing the strangling means associated with the nozzle.

Referring to the drawings by characters of reference, 1 designates acarburetor body which may be of any design suitable for the purpose, thesame having a restricted passageway preferably formed by a Venturi tubetlne end of the body forming the passagewa y mentioned constitutes anair inlet 2, and the other end 2 constitutes an outlet leading to theengine intake, not shown. The outlet F?" is provided with throttle valve3 preferupon central transverse shaft to l t chamber to a noaalc withinthe re or body, ltrality in, st which, 'l', is se tegral with the baseof the body 1, in which plug is drilled a calibrated orifice 9communicating with said conduit 5 heretofore de scribed. The innermosttube 10 of the nozzle is arranged concentric with the tube "f heretoforedescribed, and passes through a central hole 11 in the top of said tube7, and at its lower end is threaded into a counterbored hole 12 in theplug 8 and located above and in communication with the orifice 9. Thetube 10 extends for a suitable distance beyond the upper end of saidtube 7, and has its upper end 18 located adjacent the throttle valve 3and preferably so as to open through a central hole in the latter, thetube l0 thereby constituting an idling and low speed passageway for thefuel, through which an explosive mixture may be projected into theoutlet 9 when the throttle 3 is closed. in the end of u the tube 10above the throttle valve is a plug 14 containing a restricted outletorifice l5. Said tube is also provided with an orifice 16 in its sidewall for admitting air from below the throttle to the interior of tube10 to emulsify the fuel passing therethrough, as will be hereinafterdescribed.

1? designates a downwardly tapered tube surrounding and adjacent theinnermost tube 10, and spaced therefrom to form an annular chamber 18 ofprogressively decreasing crossscctional area from the upper to the lowerend thereof. The upper end portion of the tube l?! is flared outwardly,as at l9, to provide a flange, the periphery of which is arranged incontact with the inner surface of the outer tube-7, and the lower end ofthe tube l? is similarly dared to provide a flange 20 to contact withthe inner surface of the lower end of the tube 7. A fourth tube at isplaced between the tapcring tube 1? and the outermost tube 'f, and isprovided with longitudil u external grooves see lFi uni 4mm l cal airducts treniities of the tu tube if, as shown in k suitably secured tog usoldering, or other means, the fluid tight struc I in the wall which theliquid fuel Ell Eli

llllll 2 through discharge. holes 26 peripherally arranged in a roundedor cupped portion 27 at the upper end of the outer tube 7.

For the purpose of affording communication from the atmosphere to themain well 18, the outer tube 7- is provided, preferably adjacent itsbase, with air holes 28 which communicate with the lower ends of thevertical ducts 23 formed by the grooves 22 in the tube 21. At the upperend of the tube 21 are ports 29 located above the normal fuel level andat fording atmospheric communication between the ducts 23 and theannular chamber 30 located between the tapered tube 17 and the tube 21.

The tapered tube 17 is provided with ports 31 also located above thenormal fuel level and allowing communication between the chamber 30 andthe fuel well 18. These holes are preferably of such size and number asto admit the requisite quantity of air to emulsify the fuel as it issuesthrough the discharge orifices 26 under the suction of the engine. Thetapered tube 17 is also provided with a hole 32 located near the lowerend portion thereof, for the purpose of affording atmosphericcommunication with the lower end of the main fuel well 18. This orificeor hole 32 determines the rate at which the liquid fuel lowers in theWell 18 and, therefore, the cross-sectional area of liquid fuel exposedto the .aspirating air entering the holes 28. 29 and 31. The area andposition of hole 32 lengthwise of the tapered well 18 can be varied tomeet the requirements of the motor upon which the carburetor is to beused. For example, for average automobile motors, the size of the hole32 is such that the liquid level of the fuel in well 18 will not belowered to approximate the level of said hole until the engine speed hasreached approximately 800 revolutions with the throttle wide open,giving a car speed of about fifteen miles per hour.

The port 16 in the idling tube is located at a suitable point betweenthe fuel outlets 26 from the main nozzle and the throttle plate 3, whichport 116 communicates with an air tube 33 seated in the wall of thecarburetor body and having a port 34 communicating with one end of anair duct 35 extending through the body, and the opposite end of whichopens, as at 36, into the suction passage 2 at a point above said airtube. 33, but below the throttle. Threaded into the body is a screw-plugvalve 37 adapted to cooperate with the port 36 in order to regulate thearea thereof and thereby control the flow of air therethrough. It willbe understood that the tube 33 is closed at its inner end and is sealedaround the idling tube 10, the well 18 and the chamber 30 to a heightcorresponding with the level of the fuel in the float chamber, that isjust below the openings 29 as indicated by the broken line LL on Figs. 1and 2. During idling, and at low speeds, when the throttle is nearlyclosed, liquid fuel is delivered to the engine only through the innertube 10, since this tube extends above the throttle. The fuel passingfrom tube 10 is emulsified by the air which onters tube 10 through theport 16, tube 33, duct 35 and valve regulated port 36. As the throttleis opened wider and the speed of the engine increases, the suction atthe throat of the venturi increases, causing the fuel to be drawn oraspirated through the main discharge orifices 26, this fuel beingemulsified by the air which enters through the holes 28 in the outertube, passes up through the vertical ducts 23 and is admitted above thefuel in the well 18 through the ports 29 and 31.

At low speeds when the suction in the suction passage is relatively lowthe level of the fuel in the main well 18 remains near the upper endthereof at apoint just below the openings 29 and a relatively largersurface area of fuel is, therefore. exposed to the aspirating effect ofthe air passing through the holes 31 and the Vent-uri tube, with theconsequent effect of supplying the somewhat richer mixtures required forlow speed operation. As the speed is progressively increased, the levelof the fuel in the main well 18 is lowered approximately to hole 32, dueto a difference in pres sure brought about by the atmosphericcommunication afforded by holes 28, ducts 23, ports 29, chamber 30 andhole 32, and because of the tapering construction of the well whichcauses the cross-sectional area of the well to gradually decrease to thelevel of hole 32, the surface area of the fuel is diminished. Theminimum surface area of the liquid in the well 18, when the motor isrunning at higher speeds, may be secured by properly locating the hole32 lengthwise of the tapered well. By the construction described it isassured that the quantity of fuel discharged is proportional to thecross-sectional area of the liquid fuel P .posed to the aspiratingeffect of the air passing through the Venturi tube, and, therefore. myinvention effectually overcomes the well known tendency of a single jetcarburetor to supply an over-rich mixture at higher engine speeds, andassures substantially correct m x ture proportions of liquid fuel andair throughout the range of operative engine speeds and 10a. s.

When the engine is running idle and the throttle plate 3 is closed, theair pressure beneath the throttle plate will be substantiallyatmospheric. and there will be a depression on the engine side of thethrottle plate. Under these conditions air will be drawn through theport 36. into the duct 35', the bore of the tube 33, and through theport 18 into the idling natures tube 10 to min with the liquid fuelflowing through the latter, and thus provide a proper mixturev for theengine while running idle.

The construction just described also serves to prevent any lag in liquidfuel flow btween the time the throttle plate is opened and the beginningof fuel flow from the main nozzle. ll hen the throttle is suddenlyopened from the idling or nearly closed position, the air flowingthrough the suction passage 2 passes through the space between thethrottle plate and the wall of the passageway at a co1nparalively highvelocity, and passing the port 36 serves to draw the liquid fuel fromthe idling tube through the port to, tube 33, passage and said port as,thereby enriching the mixture for a short time so that there is no lagin the supply of proper mixture between the time the throttle plate isopened and the main nozzle begins to function.

shown in Figs. 1 and 8, the preferred embodiment of the carburetor maybe, and

-preferably is, provided with a movable till strangling device forchokingthe passage through the carburetor when the engine is started. Asshown, this device may consist of a cone-shaped member 'l slidablymounted upon the outer sleeve 1 of the nozzle, said device being, duringthe running of the en'- gine, adapted to rest at the base of the nozzle,but when starting, to be lifted by a suitable yolre l and lover l, saidlever being fulcrumed in ears 'l on. the body, and adapted to beoperated manually by any suitable con ction to the dashboard of thevehicle.

in the modified construction as illustrated in Fig. 6, a boss 32%projects into the air passageway and has a cylindrical outer tube 39extending upwardly therefrom. A. tubular plug lid is threaded, as 4:1,into boss 38 and has a tubular tapered upper portion t2 extendingthrough the tube 39 to form an annular chamber therebetween. taperingthe portion t2 externally, the Clittl11- ber 4:3 is formed toprogressively decrease in cross-sectional area from the top to thebottom. Fuel which is delivered through the lateral passageway 5 entersthe bore of the plug 40 through a restricted or calibrated orifice 4a,and is conducted to the bottom of p the well id-through the radial portsto in said portion 42. in the plug portion 42 below said ports 4th is anannular external groove l6, said groove communicating with the externalatmosphere through a passageway t7 in the carburetor body, and with theeel 43, by reason of the clearance 45 between the inner wall of boss 38and the up per portion of plug 40. A cap 48, secured to the tube 3tl, isprovided with discharge orifices 49, preferably located opposite therestricted portion of the Venturi tube. The

groove 46 corresponds in function to the port 32 in the form shown inFigs. 1 and 2.

In this embodiment of the invention an idling tube, functioning in thesame manner as that heretofore described, is employed. This tube isshown at 50 and is threaded, as at 50*, at its lower end into a seat 51in the upper end of the plug portion 42. The tube at its upper endprojects through a central opening 52 in a pivoted throttle plate 63,the outlet end of said idling tube terminating beyond the throttle platein the direction of travel of the mixture. 'llhis idling tube isprovided preferably with a restricted air inlet 16 constructed andarranged in connection. with an air tube 33 and asso ciated parts, asheretofore described, regard ing tubes 10 and 33.

lln ll ig. 'l" l hare shown another embodiment of the same inventionwhich, in general respects, is similar to that shown. in Fig. ti, exceptas to the nozzle structure, which will now be described. lln this form,the carbure tor body is provided within the passage 2 with a boss 5a, inwhich is threaded plug 55 having a calibrated orifice 56 communicatingwith the passage 5, heretofore de (scribed, and leading to the floatchamber.

ln the upper portion of the boss 54; is thread ed, as at 5?, the lowerend of tubular nozzle body till having a central. bore 59 which tapersdownward from the upper end of the nozzle body toward the lower endthereof. l lntending through the tubular bore 59 just described, is anidling tube 66, the lower end of which is threaded, as at til, into theplug 55, whereby said tube will. be fed liquid fuel through thecalibrated orifice 5t and the passage ii. The tube 60 is otherwisearranged and operates as heretofore de scribed, and, therefore, nofurther specific description thereof is thought. necessary. [ad jacentits lower end the tube 66 is provided with one or more ports 62correspondingto port 25 in l igs. It and 2 and which communicate with anannular passage between the outer surface of the idling tube and theinner surface of the tapered l ire tid, so that liquid fuel will passfrom the idling tube into the lower part of the tapered chamber or boretill. lln this form of the invention an air supply passage tlihtlt,preferably constructed in the same manner as the supply d7 heretoforedescribed, is supplied, and op crates in substantially the same manneras the latter.

lln both of the constructions shown in Figs. 6 and '7, it will be seenthat the some novel features are incorporated as embodied in thepreferred construction shown in Fig. 1. In both the latter instances,the tapering walls l3 and 59 receive the fuel supply at the bottomthereof, and each ofsueh wells is connected with an air tubecommunicating with the external atmosphere. lly employment of the.elongated tapered well, I am able in a single well structure to providefor the maximum fuel surface area desirable for slow ltltl speeds, and aminimum fuel surface area desirable for higher speed. The tapered wellalso provides an expansion chamber beginning at the base thereof, inwhich the fuel is more efficiently broken up or emulsified than is thecase with a plain or cylindrical fuel passage or well.

What I claim and desire to secure by Letters Patent of the United Statesis 1. A carburetor comprising a suction pas-- sage, a fuel supplyreservoir, a fuel nozzle in said suction passage and including a fuelwell having a discharge outlet communicating with said suction passageand a fuel supply inlet communicating with said reservoir, an air inletport to the well near its top and above the normal fuel level therein,said well progressively increasing in cross-sectional area from saidfuel supply inlet toward said fuel discharge outlet, said well beingadapted to hold liquid fuel substantially at the level of said airinletport and at a point of its greater cross-sectional area during lowerspeeds, and a second air inlet port to afford atmospheric communicationwith said well near its bottom and at a point of smaller cross-sectionalarea whereby the liquid level in the well is lowered adjacent saidsecond air inlet port and to a point of smaller cross-sectional areaduring higher speeds.

' 2. A carburetor comprising a suction passage, a fuel supply reservoir,a fuel nozzle in said suction passage and including a tubular memberhaving a discharge outlet communicating with said suction passage and afuel supply inlet communicating with said reservoir, said tubular memberforming a liquid fuel well of increasing cross-sectional area from saidfuel supply inlet toward said discharge outlet, an air inlet port forsaid tubular member adjacent its upper end and above the normal. fuellevel therein, said well being adapted to hold liquid fuel at a point ofits greater cross-sectional area and at the level of said inlet portduring lower speeds, and

a second air inlet port to afford atmospheric communication with saidwell adjacent said fuel supply inlet, whereby the liquid level in thewell is lowered'adjacent said fuel supply inlet and to a point ofsmaller cross-sectional area during higher speeds.

3. A carburetor comprising a suction passage, a fuel supply reservoir, afuel nozzle in said suction passage'and including a tubular memberhaving a discharge outlet communicating with said suction passage and afuel supply inlet communicating with said reservoir, said tubular memberforming a liquid fuel well of increasing cross-sectional area from saidfuel supply inlet toward said discharge outlet, said well being adaptedto hold liquid fuel at a point near its top of greater cross-sectionalarea during lower speeds, a restricted fuel feed orifice between saidwell and reservoir, an air supply port communieating with said wellabove the normal fuel level therein, and a ort to afford atmosphericcommunication wit said well near said fuel supply inlet.

4. A carburetor comprising a body having a suction passage, a fuelnozzle in said passage and comprising a tubular element constituting afuel well provided with a fuel inlet and with an outlet discharging intothe suction passage, said well increasing in cross-sectional area fromsaid inlet toward said outlet, a tube surrounding said well and spacedtherefrom to form an intermediate chamber, said chamber havingcommunication with said well at a point below the normal fuel level,said tube having an external groove extending longitudinally thereof andalso having an opening from said groove into the said intermediatechamber, and a tube surrounding said first-named tube and closing theopen side of said groove to form an air duct and having an air inletdelivering atmospheric air into said air duct.

5. A carburetor comprising a body having a suction passage, a fuelnozzle in said passage and comprising a tubular element eonstit-uting afuel well provided with a fuel inlet and with an outlet discharging intothe suction passage, said well increasing in crosssectional area fromsaid inlet toward said outlet, a tube surrounding said well and spacedtherefrom to form an intermediate chamber, said chamber havingcommunication with said well at a point of smaller cross-sectional areaand below the normal fuel level of said well, said tube having anexternal air duct extending longitudinally thereof and also having anopening from said air duct into the intermediate chamber at a pointabove the normal fuel level in the well, said well having an air portcommunicating with said intermediate chamber at a point above the normalfuel level in the well, and a tube surrounding said first-named tube andhaving an air inlet delivering atmospheric air into said air duct.

6. A carburetor comprising a body having a suction passage, a throttlecontrolling the suction passage, a main nozzle including a fuel wellhaving an outlet discharging into the suction passa e beneath thethrottle, an idling tube exten ing longitudinally through said fuel welland having a discharge outlet above that of the main nozzle, means forfeeding fuel to said idling tube and to said well, said idling tubehaving a port above the main nozzle and below the discharge outlet inthe idling tube,a by-pass passage having a port opening into the suctionpassage beneath the throttle when closed, and a tubular member extendingacross the suction passage and conmeeting said by-pass passage with saidport in the idlin tube, the arrangement and construction being such thatduring idling position of the throttle air passes from the suctionpassage through the by-pass passage and said tubular member into theidling tube, and during a portion of the travel of the throttle fromclosed toward open position fuel passes from the idling tube throughsaid tubular member and by-pass passage and is discharged from thelatter into the suction passage beneath the throttle. v

' 7. A carburetor comprising a body having a suction passage, a throttlecontrolling the suction passage, :1. main nozzle including a fuel wellhaving an outlet discharging into the suction passage beneath thethrottle when closed, an idling tube extending longitudinally throughsaid fuel well and having a discharge outlet above that of the mainnozzle, means for feeding fuel to said idling tube and to said fuelwell, said idling tube having a port above the discharge from the mainnozzle and below the discharge outlet in the idling tube, a by-passpassage in the side Wall of the suction passage and having a port at oneend opening into the suction passage beneath the throttle, and a tubularmember connecting the other end of said by-pass passage with said portin the idling tube, the arrangement and construction being such thatduring idling position of the throttle air passes from the suctionpassage through the by-pass passage and tubular member into the idlingtube, and during a portion of the travel of the throttle from closedtoward open position fuel passes from the idling tube through saidtubular member and bypass passage and is discharged from the latter intothe suction passage beneath the throttle.

In testimony whereof I have hereunto subscribed my name.

WALTER H. WEBER.

